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Projects, Designs, and Technical Stuff / Re: Design advice: Clock/pulse generator output circuit
« Last post by ch_scr on Today at 11:01:16 am »You could get the continuously variable output level with a logic gate (buffer or inverter) supplied from a variable voltage.
It's output impedance might change with supply level, but tiny gates (single inverter like 74lvc1g04) can tolerate higher drive than the supply no problem.
This in combination with (analog switch selected) attenuators could give a wide range of continuously variable output levels. Maybe no need to chain the analog switches, then.
Don't think the gate delay is of much relevance here? To drive transmission lines, you want a good match to 50R to make the square edges look clean.
This can be done by always having some minimal attenuation to improve match.
It's output impedance might change with supply level, but tiny gates (single inverter like 74lvc1g04) can tolerate higher drive than the supply no problem.
This in combination with (analog switch selected) attenuators could give a wide range of continuously variable output levels. Maybe no need to chain the analog switches, then.
Don't think the gate delay is of much relevance here? To drive transmission lines, you want a good match to 50R to make the square edges look clean.
This can be done by always having some minimal attenuation to improve match.